Mechanism for automatically setting dishwasher control switch



June 14, 1955 c. H. LVINES 2,710,515

MECHANISM FOR AUTOMATICALLY SETTING DISHWASHER CONTROL. SWITCH Filed May 21, 1955 5 Sheets-Sheet l INVENTOR.

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A TTORNE Y5 June 14, 1955 c. H. LINES 2,710,515

MECHANISM FOR AUTOMATICALLY SETTING DISHWASHER CONTROL SWITCH Filed May 21. 1953 3 Sheets-Sheet 2 INVENTOR.

" CARL H. LINES.

BY A

MAM/1 Z/MJLMA, M1

ATTQRNEYS.

June 14, 1955 c. H. LINES 2,710,615

MECHANISM FOR AUTOMATICALLY SETTING DISHWASHER CONTROL SWITCH 3 Sheets-Sheet 3 Filed May 21, 1953 INVENTOR.

CARL H. LINES.

cud M WA! ATTORNEYS.

United States Patent :1,

MECHANISM FUR AUTOMATXCALLY SETTING DISHWASHER CONTRUL SWITCH Carl H. Lines, Connersville, lnd., assignor to Avco Manufactoring Corporation, Cincinnati, Ohio, a corporation of Delaware Application May 21, 1953, Serial No. 356,336

8 Claims. (Cl. 1345%) The present invention concerns an improvement for a domestic dishwasher and pertains more particularly to a simple mechanism for automatically setting the motor driven switch of the dishwasher to condition it for operation after the access door of the dishwasher has been closed and latched.

The modern domestic dishwasher usually includes a solenoid actuated water control valve, a motor driven impeller, an electrical heating element, and a solenoid actuated drain valve electrically connected to a motor driven rotary switch which establishes sequential operation of the various dishwasher components. it is desirable to rotate the electrical switch through its complete operating cycle by a small electric motor, and to deenergize the motor automatically at the end of the cycle. To produce such operation the motor may be energized through the switch itself. When the user wishes to initiate operation of the dishwasher, however, some means must move the electrical switch from the fully deenergized position assumed at the end of the operating cycle to the start position in which the drive motor is energized.

in some prior art devices, the electrical switch had to be set manually. By means of the present invention, however, manual setting of the switch has been eliminated and a simple foolproof mechanism has been provided for transferring motion from the access door of the dishwasher to the switch so that it is conditioned for operation when the door of the dishwasher is closed, as is done after the dishwasher has been loaded with dishes to be washed.

Briefly stated, the present invention comprises a small bell-crank which is pivotally secured to the frame of the dishwasher. To one end of the bell-crank is secured a pin positioned for engagement with the counter-balance arm of the access door, such engagement imparting rotation to the bell-crank. The other end of the bell-crank engages an adjustable set screw secured to a spring-loaded slider one edge of which is positioned to engage a step in a cam secured to the shaft of the motor-driven electrical switch. Rotation of the bell-crank, caused by closing of the access door, lifts the slider and imparts a few degrees of rotation to the cam thereby advancing the electrical switch to a start position.

in view of the foregoing, it is obviously an important object of the present invention to provide an improved mechanism for automatically setting the control switch of a dishwasher in response to movement of its access door.

A more specific object of the invention is the provision of a bell-crank mcchanisrn positioned for engagement with a part of the access door and designed to impart limited movement to the dishwasher control switch.

Another object of the present invention is to provide a door-actuated switch setting mechanism including a slider which is spring-biased to permit it to by-pass a switch control cam when moved in one direction but which assures engagement with a step in the cam during movement of the slider in the opposite direction.

2,710,615 Patented June 14, 1955 A further object of the invention is to provide simple means on the slider for facilitating adjustment of the mechanism during initial assembly to assure satisfactory operation within the limits of movement permitted by normal opening and closing movements of the access door.

The novel features that are considered characteristic of the invention are set forth in the appended claims; the invention itself, however, both as to its organization and method of operation, together with additional objects and advantages thereof, will best be understood from the following description of a specific embodiment when read in conjunction with the accompanying drawings, in which:

Figure l is a perspective view of a dishwasher including a front opening access door, the closing movements of which actuate the preferred switch setting mechanism;

Figure 2 is a side elevational view of the dishwasher with its lower side panel broken away to illustrate more clearly its internal construction;

Figure 3 is a vertical cross sectional view through the lower portion or" the dishwasher showing the switch setting mechanism in the position assumed when the access door is closed and the operating cycle of the dishwasher has just been initiated;

Figure 4 is a front elevational view of the mechanism shown in Figure 3;

Figure 5 is a vertical cross sectional view taken on plane 5-5 of Figure 4 showing the mounting installation of the slider, in addition [0 an adjustable set screw which is secured to the slider;

Figure 6 is a side elevational view of the lower portion of the dishwasher showing a portion of its access door in a partially opened position, the elements of the switch setting mechanism being shown in corresponding positions; and

Figure 7 is a front elevational view of the mechanism in the position shown in Figure 6.

With reference to Figures 1 and 2, there is shown a dishwasher, generally designated 1, including side walls 2, top panel 3, lower panel 4, and a forward-opening access door 5. The access door is pivoted about horizontal pins 6 (see Figures 3 and 4) and is latched in closed position by a latch mechanism actuated by handle 7.

The details of the dishwasher are set forth more fully in pending application Serial No. 288,460, filed May 17, 1952, by Lloyd H. Davidson, entitled Domestic Dishwasher Having Rotary Dishrack on Extensible Bracket.

It will be sufficient for the purposes of the present invention to understand that the dishwasher includes dish retaining raclts above impeller 3 locatedin the lower portion of vat, or tub, 9. An electric motor 10, depending from the tub, drives impeller 8.

The dishwash i also includes an electrical resistance type heating element ii and a solenoid actuated drain valve 12. in addition to a solenoid operated inlet water valve, which has not been illustrated. The impeller, motor, heater, and electrically controlled valves are connected to a. source of power through a motor driven rotary electrical switch, generally designated Switch 13 establishes sequential connections between the source of power and the various valves and operating elements of the dishwasher. During rotation of impeller 8, water is thrown forcefully up through the racks and against the dishes, thoroughly washing all articles within the dishwasher. fter the washing operation has been completed, heater 11 may be energized to warm the air within the dishwasher to accelerate drying of the dishes. Improved drying can also be attained by forcefully circulating the warmed air by simultaneous operation of the impeller 8. As will be understood by those skilled in the art, the inlet and drain valves are also operated in sequence to rinse food particles from the dishes and to supply the water charge which is thrown against the dishes by the impeller during the washing portion of the cycle.

The exact sequence of operation of the dishwasher components is not important for the purposes of this invention. It is important, however, to understand that a predetermined cycle of operation is established by a plurality of switch contacts (not shown) within electrical switch 13.

Switch 13 is of the rotary type and includes a control shaft 14 which projects through the lower panel 4- of the dishwasher for engagement with a manual control knob 15. A switch drive motor 16 rotates shaft 14 and advances the electrical switch through its cycle of operation. An overrunning clutch is provided between motor 16 and shaft 14 to make possible manual change of the switch setting through the use of knob 15. In this way, the switch may be advanced to any desired point of its operating cycle to meet particular require ments of the user.

Attention should now be directed to Figure 4 which shows a cam 17 secured to shaft 14. This cam rotates with shaft 14 whenever the switch drive motor 16 is energized, the cam advancing from a start position, illustrated in Figure 4, clockwise through approximately 345 to the position illustrated in Figure 7. During this rotation of the cam, the switch energizes the various components of the dishwasher sequentially and maintains a flow of current to the switch drive motor 16.

When shaft 14 and cam 17 have reached the position indicated in Figure 7, the supply of current to motor 16 is cut otf and the cam comes to rest, as indicated.

Before another dishwashing cycle can be initiated, shaft 14 must be rotated approximately 15 to the position indicated in Figure 4 in which electrical connection is again established by switch 13 for energizing motor '16 provided an interlock switch, hereinafter described, associated with handle 7 is closed. The mechanism for rotating cam 17 to advance the switch will now be considered.

With particular reference to Figures 3 and 4, it will be noted that a counterbalance arm 18 is secured for conjoint rotation to access door 5 of the dishwasher. Arm 18 passes through a slot 19 formed in the front wall of dishwasher frame member 20. Pivotally secured to the frame member, as at 21, is a bell-crank 22 including an outstanding pin 23 which passes through a transverse slot 24 into position for engagement with arm 18. When the access door 5 of the dishwasher is in the closed position, illustrated in Figures 3 and 4, pin 23 is engaged by the arm 18 and bell-crank 22 is biased counterclockwise, moving its outstanding arm 25 towards an adjustable set screw 26. As illustrated in Figure 5, a small horizontal projection 27 on arm 25 of the bellcrank engages the set screw which is threadedly engaged with nut 29 secured to slider 28. The set screw is a close fit with the nut to preclude change of adjustment resulting from vibration.

lider 28 is well illustrated in Figures 4, 5, and 7. With reference to these figures, it will be noted that the slider includes a vertical portion 28a and horizontal projections 30 and 31 set screw 26 passing through projection 30.

A tension coil spring 32 is stretched between projection 31 and anchor member 33 which is secured to structural element 36 of the dishwasher. Spring 32 constantly urges slider 28 toward the bottom of the dishwasher. Movement of the slider is guided by a rivet 34 which is loosely engaged in vertical slot 35 formed in structural member 36. (See Figures 3, 5, and 6.)

From a study of the various figures, it will be understood that when access door 5 is closed bell-crank 22 is urged counterclockwise and an upward movement is transferred through adjustable set screw 26 to slider 28. When the access door is open, bell-crank 22 is moved clockwise by the force of spring 32 which pulls slider 28 down against projection 27 of arm 25 of-the bell-crank. i'

Attention should now be directed to step 37 which is formed in the periphery of cam 17. This step is engaged by projection 31 of slider 28 when the slider is raised by closing the access door. Thus, when the dishwasher has been loaded and door 5 is moved to a closed position, slider 28 is carried into engagement with step 37 and sufficient rotation is imparted to cam 17 to rotate shaft 14 and the associated electrical switch to a position where electrical connection is made to switch drive motor 16.

It hasvbeen found desirable, although not necessary, to provide a small spring steel clip 38 on projection 31 to provide a smooth hardened wear surface at the point where the slider engages the surface of cam 17.

It is convenient to provide, in series with switch 13, an electrical interlock switch associated with handle 7 so that drive motor 16 and other components of the dishwasher cannot be operated unless the access door is properly closed.

From the foregoing, it will be appreciated that during operation of the dishwasher, cam 17 advances in the direction indicated by the arrow from the position shown in Figure 4 to the position illustrated in Figure 7, at which position the cam comes to rest. When the access door is subsequently opened, slider 28 is moved downwardly by spring 32 and projection 31 of the slider rides along the cam surface until it comes to rest in position beneath step 37, as illustrated in Figure 7. During the movement of the slider it must also rotate slightly which is possible by virtue of the single mount ing rivet 34 interconnecting the slider and its supporting member. When the access door is closed subsequently, member 18 swings the bell-crank clockwise and raises the slider whereby cam 17 is advanced to the starting position illustrated in Figure 4, as has been explained.

During initial assembly of the dishwasher, it is necessary to establish a preferred relationship of parts so that the switch 13 will be properly set when the access door is closed. Initial adjustment of the mechanism is readily effected through adjustment of set screw 26 by means of which a preferred location of the slider relative to the cam can be attained with the access door in closed position.

In view of the foregoing description of this invention, it will be appreciated by those skilled in the art that a very simple, convenient, inexpensive, novel, and foolproof mechanism has been provided for automatically setting the dishwasher control switch in response to movements of the access door. Through the novel structure disclosed, it is not necessary for the user to remember to set the switch manually in order to initiate the operating cycle.

Having described a preferred embodiment of my invention, I claim:

1. In combination in a dishwasher having a hinged access door and electrically actuated components, an electric switch resetting mechanism comprising a rotary electric switch, an external cam secured for conjoint rotation to said switch, a step formed in the periphery of said cam, a slider pivotally and slidably secured to the dishwasher and bearing on the periphery of said cam, a bell-crank having one arm positioned for engagement with said slider and the other arm positioned for engagement with a portion of the access door whereby closing movements of the door impart limited rotation to said bell-crank and corresponding movement to said slider, resilient means for maintaining said slider in bearing engagement with the periphery of said cam, movement of said slider resulting from bell-crank movement being transferred through said step of said cam to said electric switch whereby it is reset for dishwasher operation.

2. An automatic switch resetting mechanism for incorporation in a dishwasher including a pivoted access door and a plurality of electrically actuated components comprising a rotary electrical switch for selectively energizing the dishwasher components, an outstanding rotary shaft projecting from said switch, a stepped cam secured to said shaft, a slider pivotally and slidably secured to the dishwasher adjacent said cam, resilient means engaging said slider urging it towards the bottom of the dishwasherat all times, and a bell-crank engageable by the access door for transferring upward motion to said slider in opposition to said resilient means whereby said slider engages said cam and imparts limited rotation to said shaft, said bell-crank being swung into engagement with said slider through movement of the access door.

3. In combination in a dishwasher having an access door and a plurality of electrically actuated components, a rotary electric switch for sequentially energizing the components, a shaft projecting from said switch and rotating conjointly therewith, cam means secured to said shaft, a slider pivotally secured to the dishwasher adjacent said cam, and a bell-crank having one arm cooperatively disposed with said slider and the other arm in position to be engaged by the access door during its closing movements, swinging movements of said bellcrank resulting from closing of the access door lifting said slider and imparting limited rotation to said cam whereby said electric switch is reset for operation.

4. Apparatus as defined in claim 3 and, in addition, an adjustable set screw threadedly engaged with said slider in position to be engaged by the associated arm of said bell-crank whereby the relative positions of said slider, cam, and bell-crank can be established during assembly.

5. In combination in a dishwasher having a hinged access door and a plurality of electrically actuated components, a switch resetting mechanism comprising a rotary switch designed to rotate during dishwasher operation and to come to rest in a predetermined position at the end of the cycle of operation, a slider movably secured to the dishwasher arranged for engagement with a portion of said switch during movement in one di rection and to by-pass said switch when moved in the opposite direction, and a bell-crank linkage for transferring motion from the access door to said slider whereby closing movement or the door urges said slider in a. direction to engage said switch and reset it for repetition of the dishwasher cycle of operation.

6. In combination in a dishwasher having an access door, a rotary electrical control switch which comes to rest in a predetermined position at the end of a cycle of operation of the dishwasher, mechanical means for engaging a portion of said switch after it has come to rest, and means for transferring motion from said access door to said first-named means when the door is closed whereby limited rotation is imparted to said switch and it is reset for another operating cycle.

7, In combination in a dishwasher having a movable access door, movable switch means for establishing operation of the dishwasher, said switch means coming to rest in a predetermined position at the end of the dishwasher cycle of operation, mechanical means for engaging said switch in its position of rest, and means for transferring motion from said access door to said first-named means whereby it imparts movement to said switch to reset it for another cycle of operation in response to closing movements of the access door.

8. In combination in a device having a cabinet and a movable access door, means within the cabinet for performing a sequence of operations, movable switch means for establishing the sequence of operations, said switch means coming to rest in a predetermined position at the end of the sequence of operations, mechanical means for engaging said switch in its position of rest, and means for transferring motion from said access door to said first-named means whereby it imparts movement to said switch to reset it for another sequence of operation in response to closing movements of the access door.

References Cited in the file of this patent UNITED STATES PATENTS 2,468,584 Wotring Apr. 26, 1949 2,575,704 Clark Nov. 20, 1951 2,618,282 Stanitz Nov. 18, 1952 2,659,782 Wolf Nov. 17, 1953 2,675,010 Hollerith Apr. 13, 1954 

